Speedlite Transmitter ST-E2
With the Speedlite 550EX and the Speedlite Transmitter ST-E2, it is now possible to use multiple Speedlites under full E-TTL control and without the need for any interconnecting wires. Developed in conjunction with the Speedlite 550EX and the EOS-3 camera, this master control device for a wireless Speedlite flash system meets professional and advanced amateur standards. Its dedicated transmitter controls up to 3 Canon 550EX Speedlites as slave units 33 feet away outdoors and 49.5 feet away indoors. It is mounted as a clip-on with a shoe lock lever and locking pin.
Offer valid October 26, 2014 12:00 a.m. through December 31, 2014 11:59 p.m. ET. Offer valid in U.S.A. only, and void where prohibited, taxed or restricted. Availability of certain items may be limited. Limit of ten of any one item per order, subject to availability. Order will be shipped to a street address in the 50 United States or the District of Columbia only. Dealers, distributors and other resellers are not eligible for this offer. Offer subject to Canon Online Store Terms of Sale.